Yes, it was late! Inversion, not transformation, but not directly relevant;
just the alternating signs. And yes, I probably learnt about the intersecting
sets but had forgotten. Googling intersecting rectangles or cuboids didn’t
reveal much of use. So I was quite pleased with my (re)discover
I thought I'd try running this code, but it failed on parse. Must have
been my data, I thought,
so I tried parse sample, which is defined in the following script.
parse sample
|assertion failure
| 7=#t-._ __
I'm running J903-a, same as Raul, I think, under Windows 11, which is
di
Whoa! I've just tried
use sample
which did work ok.
Mea Culpa
Mike
On 12/01/2022 13:24, 'Michael Day' via Programming wrote:
I thought I'd try running this code, but it failed on parse. Must
have been my data, I thought,
so I tried parse sample, which is defined in the following script
I didn't get a grip on this problem at the beginning and skipped it.
But inspired by Raul's solution it appeared that the problem input looks
like an encoded LISP expression.
So I tried to parse the data into a LISP-like J expression and was
wondering if I could then apply ". on it.
The parsing ver
OK, sorry about the alarm just now. I'd misunderstood how to apply parse.
FWIW, I ran b22 and my "reboota" on "sample" which I'd called
"bigexsteps" (big example steps)
and on my bespoke data set, called "data" for some reason. "reboot2a"
is a much slimmer version
of "reboot2". reboot2 perf
I think you could use X ;: bits where bits is a sequence of '0' and
'1' characters, if you used ;: opcode 6 (stop) on reaching the payload
part of the packet.
An example implementation would then interpret the first word of the
result as the puzzle opcode. If the opcode was 4, it would interpret
t
I've now modified reboot2a - it's now reboot2b (!) - to accumulate
volumes of repeated intersection cuboids.
It performs significantly better than reboot2a, whose time & space I
reported earlier, in the msg below this one:
ts'reboot2b data' NB. ~6x faster, ~5x smaller
0.229044 1.2546
https://adventofcode.com/2021/day/23
For day 23, we needed to solve a lazy shrimp problem.
We had a room and hallway setup (view in monospace font):
sample=:];._2 {{)n
#
#...#
###B#C#B#D###
#A#D#C#A#
#
}}
Ignore spaces and '#' (wall) characters. The important loc
